name = "tan feng"
print(name)
print(name.title())
print(name.upper())
print(name.upper().lower())
print('name: ' + name)

print("name: tf ".rstrip())
print("  name: tf".lstrip())

print("tf age: " + str(24))
print(2 + 6)
print(2 ** 3)
print(2*4)
